JPH0444739B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a silver salt offset printing plate, and more specifically, it is a direct printing plate that can be used immediately as a printing plate by making the silver image obtained by the silver salt diffusion transfer method ink receptive. This relates to offset printing plates. [Prior Art] Various methods have been known for producing the above-mentioned offset printing plates, but the most representative one at present is the one in which the photosensitive element and the printing image element are integrated, for example, the method disclosed in Japanese Patent Publication No. 1973 (1973). −42453 Publication, 48
The method described in Japanese Patent No. 30562 is also widely known. That is, a hydrophilic colloid layer mainly consisting of a photosensitive silver halide emulsion is coated on a support, and a physical development nucleus layer (described later) which becomes a printing image element is coated on top of the hydrophilic colloid layer. By transferring and developing, an ink-receptive lipophilic silver image is formed on the outermost surface. Such offset printing plates consist of a lipophilic part that accepts ink and a hydrophilic part that repels ink, and a good offset printing plate requires a large difference between lipophilicity and hydrophilicity. be done. That is, it is important that the ink adhesion to the lipophilic image areas is excellent and that the ink does not stain the hydrophilic non-image areas. In addition, increasing the sensitivity of printing materials themselves is also an important technology, and especially in recent direct plate making, the development and application of laser light or light emitting diode light sources has made it possible to add color sensitivity compatible with these light sources. At present, there is a strong demand for increased sensitivity and higher sensitivity. Under these circumstances, many proposals have been made to improve ink receptivity, increase printing durability, and increase sensitivity. Publication No. 56-9749 or Japanese Unexamined Patent Application Publication No. 53-21601 using a spectral sensitizer, No. 56-
Publication No. 110927 is known. However, as mentioned above, offset printing plates
Printing is achieved by a delicate balance of surface properties, and in the case of silver salt diffusion transfer offset printing plates in particular, the photographic development characteristics of the plate material itself,
Alternatively, changes in the physical properties of the layers greatly affect the printability, and the current situation is that even with these techniques, a fully satisfactory plate material has not yet been obtained. In addition, in the case of offset printing plates using the silver salt diffusion transfer method, in order to increase the development speed and avoid oxidation of the developing agent in the developer, it has traditionally been done to incorporate the developing agent into its constituent elements. ing. However, when a developing agent is contained in a light-sensitive material, it is unavoidable that the developing agent is oxidized in the air to some extent in the layer, which causes undesirable development such as deterioration of developability, increased fog, and soft contrast. It is customary. Particularly in the case of silver salt diffusion transfer method offset printing materials, problems such as a decrease in contrast and the occurrence of fog occur during raw storage of the materials, making it impossible to form a sufficient lipophilic image as a printing plate. Furthermore, it is generally well known that spectral sensitization using cyanine or merocyanine dyes is a means of expanding the sensitive wavelength range of silver halide and increasing its sensitivity. Cyanine dyes are of the amidinium ion type as shown in the general formula [ ] below, and have an alkyl group or a substituted alkyl group attached to the two nitrogen atoms, depending on the type of substituents. It is also well known that it greatly influences the sensitization and aggregation properties of dyes. In recent years, substituted alkyl groups such as sulfoalkyl groups or carboxylalkyl groups have become mainstream as the nitrogen atom substituents R ¹ and R ² in the following general formula [], as alkyl groups into which a hydrophilic group has been introduced. The reasons for this include reduction in dye staining and interaction with other types of additive chemicals for photography, and are currently widely used. General formula [] [Z ¹ , Z ² , R ¹ , R ² , R ⁰ and X in the formula have the same meanings as in the general formula []. ] The technical field of the present invention is no exception, and offset printing characterized by containing an anionic betaine type cyanine dye containing a water-soluble alkyl group, such as the above-mentioned JP-A-53-21601 and JP-A-56-110927, etc. I have the ingredients. However, when these dyes are used in silver salt diffusion transfer offset printing materials containing the above-mentioned developing agent, the above-mentioned contrast reduction and fogging are likely to occur during storage, and improvement is desired. was. The inventors have filed all patent applications filed in 1983-
Specification No. 134400 (see Japanese Patent Application Laid-Open No. 59-24851)
proposed the use of a combination of specific oxacarbocyanine dyes and merocyanine dyes to improve this drawback, but subsequent research revealed that the sensitization was still insufficient and that the ink receptivity was insufficient. However, the results were not necessarily excellent under harsh conditions. [Object of the Invention] The object of the present invention is to provide a silver salt diffusion transfer method that stably has high sensitivity and high contrast photographic properties, has good ink receptivity, and has high printing durability without causing scumming. An object of the present invention is to provide an offset printing material containing a developing agent. [Structure of the Invention] The above object is to provide a silver salt diffusion transfer method offset printing material, which is constructed by laminating at least one anti-fade layer, a silver halide emulsion, and a physical development nucleus layer on the support from the support side. The above constituent elements contain a developing agent in an amount capable of developing exposed silver halide in an alkali activation bath, and the silver halide emulsion layer contains a sensitizing dye represented by the following general formula []. This was achieved by a silver salt offset printing material characterized by containing at least one of the following. That is, as a result of intensive studies on a wide range of spectral sensitization methods, the present inventors have found that the above purpose is to use a silver halide photographic emulsion containing at least one type of cationic cyanine dye represented by the above general formula []. The inventors have discovered that this can be easily accomplished by the following method, and have thus come up with the present invention. General formula [] Z ¹ and Z ₂ in the formula each represent an atomic group necessary to form a cyanine heterocyclic nucleus, specifically thiazole-based (e.g. thiazole, benzthiazole, naphthothiazole) selenazole-based (e.g. selenazole, benzselenazole) ) Oxazole series (e.g. oxazole, benzoxazole, naphthoxazole) Pyridine series, quinoline series, and imidazole series (e.g. imidazole, benzimidazole, naphthoimidazole)
etc. These heterocycles have 1 to 1 carbon atoms as substituents.
4 may be substituted with an alkyl group, an alkoxy group, an aryl group, an aralkyl group, a hydroxy group, a trifluoromethyl group, a cyano group, a carboxyl group, an alkoxycarbonyl group, a halogen atom, or the like. R ¹ and R ² are lower aliphatic groups (for example, methyl, ethyl, and propyl groups that are unsubstituted alkyl groups having 1 to 4 carbon atoms), allyl groups, aralkyl groups ( For example, benzyl group), hydroxyalkyl group (for example, 2-hydroxyethyl group, 3-hydroxypropyl group, etc.), acetoxyalkyl group (for example, 2-acetoxyethyl group, 2-acetoxypropyl group, etc.),
It represents an alkoxyalkyl group (eg, 2-methoxyethyl group, 4-methoxybutyl group, etc.) and an aryl group (eg, phenyl group). R ⁰ represents a hydrogen atom or a lower alkyl group (for example, a methyl group, an ethyl group, and a propyl group, which are unsubstituted alkyl groups having 1 to 3 carbon atoms). m, n represent 1 or 2, p is 0 or 1
It is. X is an inorganic or organic acid anion that forms a salt with the dye (e.g. chloride ion, bromide ion, iodide ion, perchlorate ion, rhodan ion, p-
toluenesulfonic acid ion, etc.). Next, cyanine dyes particularly useful in the present invention are shown by the following general formulas [] to []. General formula [] General formula [] General formula [] General formula [] R ⁰ and X in the formula have the same meanings as in the general formula []. Y ¹ and Y ² are each a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group, an aryl group, an aralkyl group, a hydroxy group, a trifluoromethyl group, a cyano group, a carboxy group, an alkoxycarbonyl group, or a halogen atom Represents a substituent such as. Q ¹ and Q ² represent integers of 1 or 4. Specific compound examples of the dye of general formula [] are: Compound (1) 5,5'-dimethyl-3,3'-diethyl-9-ethyl-oxacarbocyanine iodine salt (2) 5,5'- Diphenyl-3,3'-diethyl-9-ethyl-oxacarbocyanine rhodan salt (3) 5-chlor-5'-phenyl-3,
3'-diethyl-9-ethyl-oxacarbocyanine iodine salt 〃 (4) 5,5'-dichloro-3,3'-diethyl-9-ethyl-oxacarbocyanine iodine salt 〃 (5) 5,5'- Dimethoxy-3-3'-diethyl-9-ethyl-oxacarbocyanine iodine salt Specific compounds of the dye of general formula [] include (6) 3,3'-diethyl-9-methyl-thiacarbocyanine iodine salt (7) 3,3'-diethyl-9-ethyl-thiacarbocyanine iodide salt (8) 5,5'-dichloro-3,3'-diethyl-9-
Ethyl-thiacarbocyanine iodine salt (9) 5,5'-dimethyl-3,3'-diethyl-9-
Ethyl-thiacarbocyanine iodine salt (10) 5,5'-diethoxy-3,3'-diethyl-9
-Ethyl-thiacarbocyanine bromine salt Specific compounds of the dye of general formula [] include (11) 3,3'-diethyl-9-ethyl-β-naphthothiacarbocyanine iodine salt (12) 5,5'-di-chloro-3,3'-diethyl-9-
Ethyl-β-naphthothiacarbocyanine bromide Specific compounds of the dye of the general formula [] are (13) 5,6-dimethyl-5'-phenyl-3,3'-
Diethyl-9-ethyl-thiaoxacarbocyanine iodine salt (14) 5,6-dimethyl-5'-chloro-3,3'-diethyl-9-ethyl-thiaoxacarbocyanine iodine salt. The methods for synthesizing the above-mentioned compounds, their properties, and methods of use have been well known for a long time. For example, F. M. Written by Ham [The Cyanine]
Soybeans and Related Compounds (The Chemistry of Heterocythe Compounds, Volume 18)] 1964. Or Sea. E. K. Mies and Tee. H. It is described in The Theory of the Photographic Process (3rd edition), co-edited by James James, 1966. The present invention has a silver halide photographic emulsion layer containing these cyanine dyes, and contains a developing agent in an amount capable of developing the exposed silver halide in an alkaline activation bath. be. That is, the present invention provides that the nitrogen atom substituents (R ¹ and R ² ) in the general formula [] are hydrocarbon groups having, for example, a sulfo group or a carboxy group as a conventionally commonly used hydrophilic group. It is not a so-called anion type or betaine type dye, but an alkyl group,
By using a so-called cationic cyanine dye into which a hydrocarbon consisting of an aralkyl group, aryl group, allyl group or a derivative thereof is introduced,
The present invention significantly suppresses the softening of tone, the decrease in sensitivity, and the occurrence of fog in silver salt offset printing materials containing a developing agent, and these effects could not have been predicted from the conventional techniques. Furthermore, according to the present invention, additives such as stabilizers, development regulators, toning agents, and complexing agents which are commonly used in the silver halide emulsion and which have the ability to directly adsorb to or form complexes on silver halide grains are used. It is a great advantage that the amount can be increased and the disadvantages such as desensitization or softening of the emulsion, which had been a concern in the past, can be avoided, and the use of mercaptoazole type additives can be advantageously promoted. be. Although the mechanistic analysis of some of these advantages is not clear, compared to conventional anionic or betaine type cyanine dyes, the adsorption of the cationic cyanine dye according to the present invention to silver halide grains is This is presumed to be due to the fact that the silver salt diffusion conversion by physical development is not inhibited by the developing agent or additive chemicals, and is based on increasing the activity of the developer anions contained in the exposed area during the silver salt diffusion conversion by physical development. In addition, Japanese Patent Application Laid-Open No.
According to Publication No. 53-21601, when a cationic cyanine dye is used, diffusion transfer development is suppressed, the amount of transferred silver decreases, and development unevenness occurs on the boundary between the developed area and the non-developed area, resulting in poor printing suitability. It is disclosed that the This is understood to be based on the fact that cationic dyes act more inhibitingly on physical development than anionic or betaine dyes. However, in the developing agent-containing plate material produced by the method of the present invention, the above-mentioned physical development inhibiting property of the cationic dye acts effectively, and together with the appropriate chemical development inhibiting property in the exposed area, A high-contrast transferred silver image without silver fog can be obtained. In the method of the present invention, the above dyes are added to the silver halide emulsion by dissolving them in water or a hydrophilic organic solvent such as methanol or ethanol. The timing of addition to the emulsion may be arbitrary, but preferably before or after chemical ripening, and dye ripening (chemical ripening after adding the dye) may be performed to sufficiently improve adsorption properties. The amount added is silver halide 1
10mg to 1000mg per mole, preferably 50mg to 500mg
That's fine. The printing material of the present invention thus obtained is
By selecting the sensitizing wavelength of the dye in the above general formula [], direct plate making can be achieved using a scanning exposure light source such as various laser beams or a light emitting diode (LED). The present invention will be explained in more detail below. As described above, the silver salt offset printing material of the present invention (hereinafter simply referred to as the printing material of the present invention) has an antihalation layer, a photosensitive silver halide emulsion layer, and a physical development nucleus layer on the support. Although the basic layer structure is provided with , an intermediate layer can also be provided between each of the above layers. In the printing material of the present invention, it is preferable that in the above layer structure, a physical development nucleus layer is provided directly on the photosensitive silver halide emulsion layer. In the present invention, the antihalation layer provided closest to the support is a hydrophilic colloid layer in which, for example, carbon black, dye, or pigment is dispersed. Further, the silver halide composition of the photosensitive silver halide emulsion layer according to the present invention is preferably substantially cubic crystal silver halide containing at least 98 mol % or more of silver chloride. Such a light-sensitive silver halide emulsion containing silver halide may be a silver chlorobromide or silver chloroiodobromide emulsion containing trace amounts of silver iodide or silver bromide; Preferably, it is a pure silver chloride emulsion containing mol %. Such a silver halide emulsion may be prepared by any method well known in the art, such as a single jet method, a double jet method, or a controlled jet method. Since the silver halide emulsion according to the present invention is made up of at least 98 mol% of silver chloride grains as described above, the usual mixing method is used as long as the excess halide ion concentration during grain formation is not extremely high. Silver halide grains having cubic crystallinity can be formed in this manner. The average grain size of the silver halide in the silver halide emulsion is preferably in the range of about 0.05μ to 2.0μ. After grain formation, soluble salts are removed from this silver halide emulsion by a conventional method. The desalted emulsion can be chemically sensitized using a sulfur sensitizer such as thiosulfate, allylthiocarbamide, thiourea, allyl isothiacyanate, and the like. Furthermore, U.S. Patent No. 2399083, U.S. Patent No. 2597856, U.S. Patent No.
Gold compounds described in US Pat. No. 2597915, etc., US Pat. No. 2448060, US Pat. No. 2540086, US Pat.
The above emulsion can be ripened using noble metal salts such as platinum, palladium, iridium, rhodium, and ruthenium, which are described in Japanese Patent Nos. 2,566,263 and 2,598,079. The hydrophilic binder advantageously used in the silver halide emulsion according to the present invention is gelatin, and a part or all of the gelatin can be substituted with a synthetic high-molecular polymer such as polyvinyl alcohol, poly-N-
vinyl pyrrolidone, polyacrylic acid copolymer,
A copolymer of methyl vinyl ether and maleic anhydride, or a compound substituted with a cellulose derivative, a gelatin derivative, etc. can be used. Furthermore, various compounds may be added to the emulsion for the purpose of stabilizing it during the manufacturing process or storage, or preventing the occurrence of fog during development. Furthermore, in addition to the above compounds, for example, hardening agents,
Various additives such as surfactants can be used as appropriate.For specific compound examples, see "Product Licensing Index" Volume 92, No.
9232, pp. 107-110, ~, ~,
, (December 1971). The photosensitive silver halide emulsion layer according to the present invention can be formed by coating the emulsion thus prepared as a layer on the antihalation layer by a known method. Next, regarding the development nuclei of the physical development nucleus layer according to the present invention, for example, water-soluble noble metal salts such as gold, silver, platinum, palladium, zinc, lead, cadmium, etc.
Metal colloids obtained by reducing heavy metals such as nickel, cobalt, iron, chromium, tin, antimony, bismuth, etc., or water-soluble metal salts thereof, such as nitrates, acetates, borates,
Development nuclei obtained by mixing chloride, hydroxide, etc. with a water-soluble sulfide, such as sodium sulfide, etc. can be used. As for the type of hydrophilic binder used in the physical development nucleus layer according to the present invention, hydrophilic polymer substances of the same type as those used in the photosensitive silver halide emulsion layer described above are applicable, including gelatin, polyvinyl alcohol, Alternatively, a copolymer of methyl vinyl ether and maleic anhydride is preferred, and a combination of these may also be used. The amount of these hydrophilic binders is not necessarily uniform depending on the type of noble metal or binder, but ranges from 30% to 100% by weight relative to the physical development nuclei. The physical development nucleus layer described above is preferably coated directly on the photosensitive silver halide emulsion layer. Examples of the support for the offset printing material according to the present invention include nitrate film, cellulose acetate film, cellulose acetate butyrate film, polystyrene film, polyethylene phthalate film, polycarbonate film, laminates thereof, and paper. Furthermore, paper coated with or laminated with baryta or an α-olefin polymer, especially a polymer of α-olefin having 2 to 10 carbon atoms such as polyethylene, polypropylene, or ethylene butylene copolymer, or paper with a rough surface as described in Japanese Patent Publication No. 47-19068, It is possible to use a support formed by surface roughening to enhance adhesion to other polymeric substances, or by a surface roughening method described in Japanese Patent Publication No. 56-135840. Also, in order to reduce plate elongation, a support in which metal foil, for example aluminum foil, is laminated to paper can be used. Further, colloidal silica can be used in a coating film applied to a polyolefin surface for the purpose of improving adhesion to a polyolefin-coated surface or improving printability. Regarding these, the method described in US Pat. No. 3,161,519 may be followed. In order to strengthen the adhesion between the support and the coating amount, the surface of the support may be subjected to preliminary treatment such as corona discharge, ultraviolet irradiation, flame treatment, etc. Regarding corona discharge, the method described in US Patent No. 2018189 is representative. Hardening of the silver halide emulsion and/or other constituent layers can be carried out according to conventional methods. Examples of curing agents include aldehyde compounds such as formaldehyde and glutaraldehyde, ketone compounds such as diacetyl and cyclopentanedione, bis(2-chloroethyl urea), and 2-hydroxy-4,6-dichloro-1,3. , 5-triazine, etc. U.S. Patent No. 3288775, U.S. Patent No. 2732303
Compounds containing reactive halogens, divinyl sulfone, 5-acetyl-
1,3-diacryloylhexahydro-1,3,
5-triazine, etc. U.S. Pat. No. 3,635,718,
Same No. 3232763, Same No. 3490911, Same No. 3642486,
Compounds with reactive olefins such as those shown in British Patent No. 994869, N-
Hydroxymethylphthalimide, other N-methylol compounds as shown in US Pat. No. 2,732,316 and US Pat. No. 2,586,168, isocyanates as shown in US Pat. Aziridine compounds as shown in specifications such as No. 3017280 and No. 2983611, acid derivatives as shown in specifications such as U.S. Patent No. 2725294 and No. 2725295, and U.S. Patent No. Carbodiimide compounds as shown in US Pat. No. 3100704, epoxy compounds as shown in US Pat. No. 3,091,537, US Pat. No. 3,321,313 and US Pat. No. 3,543,292 Examples include isoxazole compounds as shown, halogenocarboxaldehydes such as mucochloric acid, dioxane derivatives such as dihydroxydioxane and dichlorodioxane, and inorganic hardeners such as chromium alum and zirconium sulfate. In place of the above-mentioned compounds, compounds in the form of precursors such as alkali metal pisulfite aldehyde adducts, methylol derivatives of hydantoin, primary aliphatic nitroalcohols, etc. may be used. If necessary, known surfactants may be added alone or in combination to the constituent layers of the offset printing material of the present invention. These may be used as coating aids, but may also be used for other purposes, such as emulsification and dispersion, acceleration of development, improvement of other photographic properties, adjustment of charge series, and prevention of static electricity. These surfactants include natural products such as saponin,
Anionic or nonionic surfactants such as alkylene oxide type, glycerin type, glycidol type, higher alkylamines, quaternary ammonium salts, pyridine and other heterocycles, cationic surfactants such as phosphonium or sulfonium,
Anionic surfactants with acidic groups such as carboxylic acids, sulfonic acids, phosphoric acids, sulfuric esters, and phosphoric esters; amphoteric surfactants such as amino acids, aminosulfonic acids, and sulfuric or phosphoric esters of amino alcohols. included. Some examples of surfactant compounds that can be used include U.S. Pat.
No. 2288226, No. 2739891, No. 2739891, No. 2288226, No. 2739891, No.
No. 3068101, No. 3158484, No. 3201253, No. 3210191, No. 3294540, No. 3415649,
Same No. 3441413, Same No. 3442654, Same No. 3475774,
British Patent No. 3545574, British Patent No. 1077317, British Patent No.
1198450, Ryohei Oda et al., "Synthesis of surfactants and their applications" (Maki Shoten, 1964)
) and A.W. Berry, Surf Your Active Agents (Interscience Publications, Inc., 1958), JP
It is described in "Encyclopedia of Active Agents Volume 2" by John Sisley (Chemical Publishing Company, 1964). The offset printing material of the present invention may contain filter dyes or anti-irradiation dyes as described in U.S. Pat.
It may contain compounds described in the specifications of No. 2956879, No. 3177078, No. 3252921, and Japanese Patent Publication No. 39-22069. These dyes may be mordanted, if necessary, by the method described in US Pat. No. 3,282,699. Furthermore, colored layers such as pigments (for example, lamp black, carbon black, fest black, ultramarine, malachite green, crystal violet) can also be used as the above-mentioned antihalation layer. The constituent layers of the offset printing material according to the present invention can be coated on the above-mentioned support using coating methods well known in the art. Examples include a dip method, an air knife method, an extrusion doctor method, and a particularly preferred method is the pea coating method described in US Pat. No. 2,761,791. A silver halide developing agent is incorporated in the constituent layers of the offset printing material according to the present invention. In this case, development after exposure can be carried out by activation treatment using an alkaline aqueous solution. The developing agent is used in the silver halide emulsion layer, antihalation layer, or adjacent layer (undercoat layer, intermediate layer).
Although it can be contained in the antihalation layer, it is most preferably contained in the antihalation layer. Note that a developer may also be included in the alkaline aqueous solution used for development. Specific compounds for the developer include polyhydroxybenzenes such as hydroquinone, catechol, chlorohydroquinone, pyrogallol, promohydroquinone, isopropylhydroquinone,
toluhydroquinone, methylhydroquinone, 2,3
-dichlorohydroquinone, 2,5-dimethylhydroquinone, 2,3-dibromohydroquinone, 1,
4-dihydroxy-2-acetophenone, 2,5
-dimethylhydroquinone, 4-phenylcatechol, 4-t-butylcatechol, 4-n-butylpyrogallol, 4,5-dibromocatechol,
Included are 2,5-diethylhydroquinone, 2,5-benzoylaminohydroquinone, 4-benzyloxycatechol, 4-n-butoxycatechol, and the like. Among these, hydroquinone and methylhydroquinone are particularly preferably used. Other developing agents include 3-pyrazolidone compounds such as 1-phenyl-3-pyrazolidone, 1-p-tolyl-3-pyrazolidone, and 1-pyrazolidone.
-phenyl-4-methyl-3-pyrazolidone, 1
-Phenyl-4,4-dimethyl-3-pyrazolidone, 1-p-chlorophenyl-3-pyrazolidone, 1-p-methoxyphenyl-3-pyrazolidone, 1-phenyl-2-acetyl-3-pyrazolidone, 1-phenyl -5,5-dimethyl-3-pyrazolidone, 1-o-chlorophenyl-4-methyl-4-ethyl-3-pyrazolidone, 1-m-acetamidophenyl-4,4-diethyl-3-pyrazolidone, 1, 5-diphenyl-3-pyrazolidone, 1-(m-tolyl)-5-phenyl-3-pyrazolidone, 4,4-dihydroxymethyl-1-phenyl-3-pyrazolidone, 4,4-dihydroxymethyl-1-tolyl- 3-pyrazolidone, 4-
Hydroxymethyl-4-methyl-1-phenyl-
3-pyrazolidone, 4-hydroxymethyl-4-
Included are methyl-1-(p-chlorophenyl)-3-pyrazolidone and the like. In addition, as aminophenols, for example, p-
(Methylamino)phenol, p-aminophenol, 2,4-diaminophenol, p-(benzylamino)phenol, 2-methyl-4-aminophenol, 2-hydroxymethyl-4-aminophenol, etc. . The above developing agents can be used alone or in combination. In particular, a combination of a polyhydroxybenzene compound and a 3-pyrazolidone compound is preferred. Although the amount of the developing agent used in the constituent layers is not uniform, it may be in the range of 0.001 g to 1 g per 1 m ² , and in the case of a silver halide emulsion layer, it is 0.01 g to 3 g per m 2 .
g/g of silver halide. Further, if necessary, the constituent layers may contain a compound called a complexing agent which tends to form a soluble silver complex salt with silver halide in the unexposed area to advantageously promote physical development. Examples of complexing agents include thiosulfates, thiocyanates, amine thiosulfates as described in US Pat. No. 3,169,962, or cyclic imides as described in US Pat. No. 2,857,276; Mercapto compounds described in Publication No. 11957/1984 can be included. The above-mentioned developing agents may be added to the coating solution after being dissolved in water or a hydrophilic solvent such as methanol, or may be added after being dissolved in a high-boiling point organic solvent or a low-boiling point organic solvent. The high boiling point organic solvent generally has a boiling point of about 180 DEG C. or higher, and includes, for example, alkyl esters of phthalic acid such as ethyl phthalate and n-butyl phthalate, or phosphoric acid esters such as tricresyl phosphate.
In addition, as a low boiling point organic solvent, it is generally about 30℃~150℃.
Those having a boiling point at °C, for example, lower alkyl acetates such as ethyl acetate and butyl acetate. Further, these high and low boiling point solvents may be used in combination, and the dissolved developing agent may be dispersed in the hydrophilic colloid by any known method. When added to the constituent layers of the offset printing material according to the present invention, it can be added directly to any layer, or dissolved in gelatin or a synthetic polymer compound such as polyvinyl alcohol, polyvinyl pyrrolidone, US patent Examples include alkyl acrylates, sulfoalkyl acrylates, and acrylic acid copolymers described in No. 3488708. When the offset printing material of the present invention is subjected to alkali activation treatment after exposure, a treatment liquid to which various substances are added can be used. Typical examples include alkaline agents (e.g. alkali metal and ammonium hydroxides, carbonates, phosphates), pH adjusting or buffering agents (e.g. weak acids and bases such as acetic acid and sulfuric acid, and their salts); Development accelerators (e.g., U.S. Pat. No. 2,648,604, U.S. Pat. No. 3,671,247)
Various pyridinium compounds and cationic compounds, potassium nitrate and sodium nitrate, U.S. Patent No. 2533990, U.S. Pat.
Polyethylene glycol condensates and their derivatives as described in British Patent No. 2577127 and British Patent No. 2950970, etc., and polythioethers as represented by the compounds described in British Patent No. 1020233 and British Patent No. 1020032. Nonionic compounds such as U.S. Patent No.
A polymer compound having a sulfite ester, as typified by the compound described in No. 3068097,
Other organic amines such as pyridine, ethanolamine, cyclic amines, benzyl alcohol, hydrazine, etc.), antifoggants (such as alkali chloride, alkali bromide, alkali iodide, and
In addition to the nitrobenzimidazoles described in US Pat. No. 2496940 and US Pat. No.
Compounds for rapid processing liquids described in specifications such as No. 3295976, No. 3615522, and No. 3597199, thiosulfonyl compounds described in British Patent No. 972211, or described in Japanese Patent Publication No. 46-41675 phenazine-N-oxides (such as those described in ``Science Photo Handbook'', pages 29 to 47 of Volume 2), and other antifoggants described in U.S. Pat.
3161513, 3161514, UK Patent No. 1030442
Stain or sludge inhibitors, and preservatives (e.g. sulfites, acid sulfites, hydroxylamine hydrochloric acids, form sulfite, alkanolamine sulfite additives, etc.) There is. Further, metal sequestering agents such as sodium hexametaphosphate and ethylenediaminetetraacetic acid, wetting agents such as saponin and ethylene glycol, and the like can be used. Furthermore, the developer contains silver halide solvents such as sodium thiosulfate, sodium thiocyanate, potassium thiocyanate, alkanolamines, cyclic imines, alkyl-substituted amino alcohols, thiourea, thiosalcylic acid, and thiosalcylic acid is produced in alkaline solutions. For example, 5-methylcarbamoylthiosalicylic acid may be contained. If it is necessary to stop the development of the offset printing material according to the invention after development, a neutralizing solution can be used. This neutralizing solution may be a normal acidic stop bath, and may have a pH adjusted to about 3.0 to 8.0. This neutralizing liquid may contain a water softener, a PH regulator, a buffering agent, a hardening agent, etc., and for the purpose of eliminating ink stains on the printing plate to be processed.
Colloidal silica or polyols may also be added. After the printing material is treated as described above to obtain a plate, various post-treatments can be carried out for the purpose of improving printability. For example, for the purpose of improving ink receptivity, US Pat.
No. 3490906, Specification No. 3161508, Special Publication No. 1977-
No. 10910, No. 48-29723, No. 51-15762, No. 52
-15762 It is processed by the method described in each publication. Hereinafter, the present invention will be explained in more detail with reference to Examples. Example 1 A coating solution having the following composition was applied as an antihalation layer onto polyethylene coated paper (corona discharge treated) having a thickness of 160 g/m ² by a dip method. [Composition of coating liquid for antihalation layer]

【table】

[Table] Dissolve the above solutions a, b and c, respectively.
After dispersing, they were sequentially mixed, and then liquid d was added to prepare a final coating liquid. After coating the above coating solution as a layer, a photosensitive silver halide emulsion layer prepared as described below was coated on this layer. The photosensitive silver halide emulsion is a pure silver vapor emulsion prepared by the usual double-jet method, chemically sensitized with a sulfur sensitizer, and then the exemplified compounds according to the present invention and the comparative compounds [a] and [b] were added as shown in Table 1 below, and then 4-hydroxy-6-methyl-1,3,3a,
An appropriate amount of 7-tetrazaindene was added. Subsequently, an appropriate amount of isoamyl-n-decylsulfosuccinic acid sodium salt was added as a coating aid to prepare an emulsion coating solution. The amount of coated silver is 0.8 in terms of silver.
g/ ^m2 . Seasoning treatment of the two-layer coated sample obtained above (left at 40℃, RH45% for 3 days)
Thereafter, a physical development nucleus layer coating solution having the following composition was applied to the upper layer of the coating layer by an air knife method and dried to obtain an offset printing material sample according to the present invention. [Preparation of coating solution for physical development nucleus layer]

[Table] After mixing the above liquids a and b at room temperature, add liquid c under strong stirring for reduction, and after 10 minutes reduce the total amount to 1
It was used as a stock solution for finishing physical development nuclei. An appropriate amount of saponin was added to this physical development nucleus stock solution to prepare a coating solution, which was coated at an amount of 2.5 mg/m ² in terms of gold. The obtained samples were left in a constant temperature and humidity chamber at 55° C. and 80% humidity at 55° C. and 80% humidity for 3 days and left in the natural environment for 3 days, respectively, and plates were made using the method described below. Exposure method Wedge exposure for sensitometry [exposure amount 100 CMS] Alkaline activation bath treatment [processing time 30℃~30℃]
sec] Composition: Finish with anhydrous sodium sulfite, potassium hydroxide, and hypowater. 50g 30g 2g Stop bath treatment [Processing time 30℃~30 seconds] Composition Sodium citrate Finish with ethylene glycol citrate water. 10g 1.0g 10g The obtained sensitometric results are shown in Table 1 below. In addition, the relative sensitivity in the table is the relative sensitivity (white light) when the natural sample of comparative dye [a] is set as 100.
The gamma is expressed by the distribution in the straight line portion of the characteristic curve.

[Table] As is clear from Table 1, even when the method of the present invention is left under severe temperature and humidity conditions,
It was found that there was little deterioration in the photographic properties, indicating that the silver image required for printing can be stably obtained even after the printing plate has been manufactured. Example 2 Samples were prepared in exactly the same manner as in Example 1 by adding the dye according to the present invention and comparative dyes (c and d below) as shown in Table 2. The obtained sample was developed in the same manner as in Example 1 without being exposed to light, and then cross-sectional electron microscopy was taken, and the number of silver lumps reduced within the silver halide layer that was not on the outermost surface was counted. The smaller the value, the less silver fog in the emulsion layer. Further, the total amount of reduced silver was expressed as an analytical value of the amount of silver per unit area.

[Table] Table 2 above shows that although the total amount of reduced silver in the comparative sample is slightly higher, it includes fogging silver in the layer, whereas the sample according to the present invention has a slightly higher total amount of reduced silver. This indicates that the outermost surface transfer silver, which is effective for printing, is the main component. Example 3 A base paper weighing 130 g/m ² was laminated with aluminum foil having a thickness of 10 microns, and the following table 3 was prepared according to Example 1 using a support with a subbing process applied to the surface of the aluminum foil. A sample like this was created. The obtained offset printing material was processed in the same manner as in Example 1 after photographing the original using a plate-making camera to obtain a printing plate. However, samples in which no developer was added to the antihalation layer were developed with the developer shown below at 30° C. for 30 seconds, and all subsequent treatments were carried out in the same manner to obtain the respective printing plates. Developer composition [Processing time: 30°C, 30 seconds] Phenidone 1.0g Anhydrous sodium sulfite 50g Hydroquinone 6.0g Hypo 2g Potassium hydroxide 30g After development and stopping, the surface of the printing plate obtained was lightly wiped with a lipophilic solution of the following formulation. After that, printing was carried out using a printing machine also equipped with a device for supplying a dampening liquid as described below. Lipophilic liquid composition 1-p-ethoxyphenyl-5-mercaptotetrazole 0.1g Ethanol 40ml Ethylene glycol 5ml Add water to 100ml Moisturizing liquid composition Ethylene glycol 100g Colloidal silica (20% liquid) 20g Boric acid 5g Sodium sulfate ( Anhydrous) 10g Add water 1 Note that the ink receptivity, ground staining, printing durability, and dampening test in Table 3 indicate the results evaluated by the following methods. Ink receptivity: As soon as the ink roller and plate surface come into contact, paper feeding begins and is evaluated by the number of prints until a good print with high print density is obtained. 〇: Obtained within 10 pieces. △: Obtained within 30 sheets. ×: Prints with high density cannot be obtained even after 50 sheets or more. Ground stains: Evaluated by the density of background stains in the white area of the 500th printed page. ○: No dirt occurs on the ground. △: Thin dirt is partially generated. ×: High concentration of dirt on the entire surface. Printing durability: Evaluated by the number of prints that are printed continuously and become defective due to a decrease in ink density, blurred images, smudges, etc. 〇: Good even after 5000 sheets or more △: From 3000 sheets Failure occurred after 4000 sheets. ×: Failure occurred after 3000 sheets or less. Dampening test After 500 revolutions of dry running with only the dampening liquid supplied onto the plate surface, printing was started by contacting ink for the first time. In some cases, the results of tests to determine how many sheets of good-quality printed matter are obtained show that the lower the number, the less fading (defective printed matter) there is, and the printing plate can be said to have a longer printing durability.

〔Effect of the invention〕

As shown in the examples above, the silver salt printing material of the present invention can maintain high sensitivity, fog-free and high contrast photographic properties without suffering from damage caused by incorporating a developing agent. In terms of printing, it is possible to obtain a printing material with excellent ink receptivity and long printing durability. Note that Japanese Patent Application Laid-Open No. 53-21601 discloses an invention in which printing characteristics are improved by using a printing material containing an anionic or betaine type cyanine dye. However, when the developer is incorporated into the constituent layers of the plate material as in the present invention, the printing characteristics cannot be sufficiently improved using the above-mentioned conventional techniques. The present invention makes it possible to obtain a printing material with improved photographic properties and printing properties by incorporating a developer and performing spectral sensitization using a cationic cyanine dye.

Claims (1)

[Scope of Claims] 1. A silver salt diffusion transfer method offset printing material constructed by laminating at least one antihalation layer, a silver halide emulsion, and a physical development nucleus layer on the support from the support side, The above constituent elements contain a developing agent in an amount capable of developing exposed silver halide in an alkali activation bath, and the silver halide emulsion layer contains a sensitizing dye represented by the following general formula []. A silver salt offset printing material characterized by containing at least one of the following. General formula [] [In the formula, Z ¹ and Z ² each represent an atomic group necessary to form a cyanine heterocyclic nucleus consisting of a thiazole ring, selenazole ring, oxazole ring, pyridine ring, quinoline ring or imidazole ring. R ¹ and R ² each represent a lower aliphatic group or an aryl group, which may be the same or different, and R ⁰ represents a hydrogen atom or a lower alkyl group. m and n represent 1 or 2, p is 0 or 1, and X is an acid residue. ]